Electromagnetic actuators are employed for solenoid valves in many fields of process and manufacturing automation. In many cases, a plurality of solenoid valves are combined in a valve terminal or in a valve block, for example for electro-pneumatic process control. Valves in a valve terminal are typically controlled by a field bus or by an individual connection. If a fault occurs in driving the valve terminal, for example on the field bus, it is technically difficult or even impossible in the case of a bus-controlled valve terminal to safely switch off individual valves or to place them in a safe operating condition. This, however, is desirable in order to be able to safely carry out, within the process chain, a protective measure initiated in the event of a fault.
EP 2 026 156 B1 discloses a module arrangement, consisting of solenoid valves, sensor modules, intermediate modules, etc., which furthermore includes a safety module. The safety module interrupts the power supply of a partial group of modules of the arrangement which directly adjoins the safety module; these modules can thus be switched off in the event of a fault. However, provision is not made for a switch-off of individual modules. In addition, the safety module is also driven via the bus of the module arrangement. When a fault occurs on the bus, a safe switch-off is not possible.